UK scientists injected mice with stem cells for 12 weeks and saw damage from heart attacks reversed – preventing heart failure. They believe a similar procedure is possible for humans.

“This research is an
early, but important, step towards understanding how we might be
able to encourage stem cells in failing hearts to repair the
damage caused by a heart attack,” said Professor Jeremy Pearson, Associate
Medical Director at the British Heart Foundation, which provided
part of the funding for the Imperial College team that conducted
the study.

“A crucial next step for this research will be to establish
if the human heart has similar heart-repairing stem cells to
those pinpointed by this method in mice.”

Heart tissue is damaged when it is deprived of blood during a
myocardial infarction. Even if the patient is revived in time,
the affected muscle becomes scar tissue, leaving the survivor
weak, breathless and susceptible to further heart attacks, and
eventually heart failure, when the organ is simply unable to pump
sufficient blood to keep a person alive.

Following one of the most promising directions in medical
research, the Imperial College team looked for stem cells – young
cells that are able to transform into specialized cells within
the body – to inject into the mice.

“We have found stem cells in the heart that have a specific
protein – called PDGFR alpha – on their surface have the greatest
potential to repair damaged hearts,” said British Heart
Foundation Professor Michael Schneider, one of the authors of the
study, which has been published in Nature Communications.

“When we injected stem cells with this protein into damaged
hearts, we saw a significant level of heart repair. Now that we
know which stem cells to use, we want to find their equivalent in
human hearts for more efficient heart repair and regeneration
after heart attacks.”

The potential of PDGFR alpha to heal the heart had been
identified in several scientific papers in the past decade, but
the next step will be more animal, and eventually, human trials.

“Future treatments could be injections of stem cells, as in
our current experiments, or use of the healing proteins that
these cells make,” Schneider said.

This is not the only pathway of stem cell research to repair the
heart, with more than 20 different human trials currently
ongoing, experimenting different types of cells and delivery
methods. While some of the studies are in the final stages, none
of the treatments have been approved by the US regulator FDA or
the European Medicines Agency for general use as yet.

According to the World Health Organization in 2012, the latest
year available, more than 7 million people died of coronary heart
disease, with a large proportion of the deaths resulting from
chronic illness that could be targeted by stem cell therapy.